1. Technical Field
The present disclosure relates to a display device and an electronic apparatus that can detect an external proximity object, and more particularly relates to a display device with a touch detection function and an electronic apparatus that can detect an external proximity object based on a change in capacitance.
2. Description of the Related Art
In recent years, a touch detection device that can detect an external proximity object, a so-called “touch panel”, is drawing attention. The touch panel is used for the display device with a touch detection function in which a touch detection device is mounted on or integrated with a display device such as a liquid-crystal display device. The display device with a touch detection function displays various button images or the like on the display device, and thereby allows information to be input by the touch panel instead of a general mechanical button. The display device with a touch detection function having such a touch panel does not require an input device such as a keyboard, a mouse, or a keypad. Accordingly, the usage thereof is increasing in portable information devices such as mobile phone as well as computers.
As a method of touch detection, various methods such as an optical method, a resistive method, and a capacitive method can be mentioned. A capacitive type touch detection device has a relatively simple structure and can realize low power consumption. Accordingly, the capacitive type touch detection device can be that can be used for a mobile device. For example, Japanese Patent Application Laid-open Publication No. 2011-138154 describes a touch panel in which a transparent electrode pattern is made invisible. Japanese Patent Application Laid-open Publication No. 2007-264393 relates to a liquid crystal display device having a light-transmissive light condensing sheet, and describes a technique for suppressing a contrasting pattern (Moire) due to interference between a prism array pitch of the light condensing sheet and a pixel pitch of a liquid-crystal display panel.
Meanwhile, in the display device with a touch detection function, a pixel of a display panel and a touch detection electrode overlap each other. In the touch detection electrode, a transparent conducting oxide such as ITO (Indium Tin Oxide) is used as a material of the transparent electrode. The touch detection electrode is transparent, but has a predetermined refraction index. Therefore, in the display device with a touch detection function, a slit hole pattern is provided in a transparent electrode pattern of the touch detection electrode, so that the touch detection electrode is made invisible and less noticeable on human eyes.
There may be a difference in optical wavelengths between light that is emitted from the pixel of the display panel, passes through the transparent electrode pattern of the touch detection electrode, and reaches a human and light that is emitted from the pixel of the display panel, passes through the slit hole pattern, and reaches the human. The difference in optical wavelengths appears as a change in color to be displayed originally, and stripes (hereinafter, also referred to as “Moire fringes”) of a color shift pattern (color Moire) may become visible according to a field angle at which the human watches the display panel.
For the foregoing reasons, there is a need for a display device and an electronic apparatus that can decrease Moire fringes due to a touch detection electrode.